Chess960 tactic on c8 (g8)
c9-10018naming tag (square·N)Opens in the app if installed, otherwise downloads the APK.
The tactical motive
Chess960 twist: use the unusual starting setup of the pieces.
Mate: a forcing sequence that ends the game — the king has no escape.
Mate in 4: a forced checkmate in four moves — every reply is covered.
A fork made possible by the Chess960 piece placement.
Difficulty 2120 ShuffleRating — expert level — few solve it at first try.
White to move — find the best continuation
How to recognize this tactic
In Chess960 the pieces start on unfamiliar squares, so tactics appear earlier and from unusual angles. Do not trust classical patterns — read the actual lines of the bishops, the rooks and the queen from where they really stand in this position.
This is a forced mating attack. Start from the enemy king: which of its squares are already covered, and which move takes away the rest while keeping the king in check? Forcing moves — checks and captures — are what turn an attack into mate.
A mate in four is a longer forced net: each of your moves is a check or an irresistible threat, and the king is driven step by step to a square where it is finally trapped. Verify that the defender has exactly one reply at every branch.
A set-up fork needs one preparing move before the fork lands — a check that drives the king onto the forking square, or a capture that lines the targets up. Find the preparation first, then the fork it makes possible.
General method: before you move, list the forcing candidates — every check, every capture, every direct threat — and calculate those first. The solution to a tactic is almost always among them.
Position on the board
White: king a2, queen g8, rook c1 c3, bishop c4 d6, pawn c2 h2 b3 f4 b5.
Black: king a8, rook a5 c8, knight b7, pawn a3 f5 h5 d7.
11 white and 8 black pieces are on the board; the puzzle position arises after move 32.
The position in numbers
White are ahead by 13 points of material (30 against 17; pawn = 1, knight and bishop = 3, rook = 5, queen = 9) — the tactic has to convert or outweigh that.
The white king stands on a2, the black king on a8.
It is White to move on move 32, with 48 legal replies to weigh — only the line that keeps the advantage solves the puzzle.
White keeps 5 pawns, Black 4. Files fully open (no pawns of either colour): e, g — natural highways for the rooks and queen. Half-open for White: a, d.
White hold the bishop pair, an edge in open lines. The White king has 2 empty squares to step to right now — the fewer they are, the closer a mating net.
Solution & explanation
Main line
32. Qxc8+ Ka7 33. Bc7 Rxb5 34. Qb8+ Ka6 35. Qa8#
Why it works
- Great move! queen to c8 keeps the pressure (#3).
- bishop to c7 develops smoothly.
- Precise: queen to b8 is the top choice (#1).
- Best move. queen to a8 is exactly what the engine plays (#).
- The line ends in a forced mate in 4.
- If instead Ka7, then Bc7 and you win the rook.
Move by move
- 32. Qxc8+ — queen to c8 (capture) with check
- Ka7 — king to a7
- 33. Bc7 — bishop to c7
- Rxb5 — rook to b5 (capture)
- 34. Qb8+ — queen to b8 with check
- Ka6 — king to a6
- 35. Qa8# — queen to a8 and it is checkmate
Types in this puzzle
Mate in 4+
A long forced mating combination.
Mate in four or longer is a marathon of forcing moves where the grip must never loosen. The tools are the same: checks, double threats and sacrifices that deny the opponent a single free tempo. Do not juggle the whole tree at once — walk the main line all the way to mate first, then verify the side branches. If somewhere the defender finds one quiet move that holds, your very first move was wrong.
Setup fork
The random setup allows a fork that classical chess never sees.
A setup fork is a double attack that exists only because of the unusual starting squares — in classical chess these targets never stand side by side. Look for pairs of undefended pieces on your opponent's back rank and for squares from which a knight or pawn hits both at once. Such forks usually appear within the first moves, before the pieces disperse. In every new position, note right away which starting pieces are defended by no one.
Win the pinned piece
The pinned piece cannot run — attack it again and win it.
A pinned piece cannot flee, which means you can win it outright by attacking it one more time. Count attackers against defenders: if you outnumber them, the piece is yours. The best extra attacker is a pawn, since it costs less than anything it might capture. Do not rush the capture — build up the pressure first, then harvest.
About this position
These pieces come from starting position #942.
SP-942 · RampartScout — King on the wing (b/g) with a knight on the rim (a/h) — the rarest family.
The king starts on b1, the rooks on a1 and c1, the queen on e1.
From b1 the king makes the longest journey Chess960 allows when castling short: five squares to g1.
The bishops stand on f1 and g1; their long diagonals reach a6 and a7 once the e- and f-pawns step aside.
Every pawn on the second rank is defended from the very first move.
The setup belongs to the RampartScout family; read right to left it becomes position 20.
The engine's main line opens with e4, putting a pawn straight into the centre.
Morozov Balance Index: 86 of 100 — class A — most balanced. Engine evaluation of the starting position: +15 centipawns for White (depth 47, 400 000 000 nodes).
Explore position #942Provenance
Mined from the project's engine self-play games.
Pack 015 · SP-942
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